Gas burner and pilot



June 28, 1949. P. J. PATCH @As BURNER AND PILOT Filed Sept. 7, 1945 INVEN TOR. PAUL J PA Tc H BY m z I /m F M.. 3 ,MUSE-MW y ATTORNEYYPatented June 28, 1949.

GAS BURNER AND lflLT Paul J. Patch, Denver, Colo., assignor to The RockyMountain Gas Equipment Company, Denver, Colo., a corporation oi'Colorado Application September 7, i945, Serial No. 614,888

4 Claims. l

This invention relates to improvements in gas lburners and pilots of thetype employed in connection with heating installations more particularlyin connection with the heating of residences.

In the heating of buildings with gas it is customary to employmulti-llame furnaces, each llame being connected with a iiue.

It is, of course, essential that the name must always be kept alive, forotherwise the thermostats will open the gas valves and fill the furnace,and 'sometimes the building, with gas, for which reasons destructiveexplosions mightloccur.

Practically every gas installation oi the automatic control type isprovided with a pilot flame that is constantly burning and which assuresthat the gas .for the main ame of the burner will always be ignited whenthe gas is turned on by the automatic thermostatic control mech anism.

In addition to the pilot iiame, the main burners are interconnected bynarrow slots forming burnn ers which carry the iiame from the pilotburner to the main burners and ignite the gas from the pilot llame.

Every burner must, of course, be provided with an automatic means forturning of! the gas to the pilot burner and to the main burners as wellin case the pilot llame for any reason is extinguished. It has beencustomary to employ a bimetallic switch mechanism for cutting on the gasto the burners when the pilot flame becomes extinguished. The bimetallicthermo-responsive valve control vhas now been superseded'in many placesby a thermal couple positioned adjacent the pilot flame to receive heatfrom it as long as it is burning. If the pilot name, however, becomesextinguished, the current generated by the thermal couple decreases andreaches a point below a predetermined value, a valve, responsive to thecurrent generated by the thermal couple, will close, cutting 01T thesupply of gas to the burners by rendering the control mechanisminoperative for the purpose of turning on the gas in response to thethermostats.

As all of the mechanisms and means referred to above are old, they havenot been illustrated, but attention has been called to them for thepurpose of more clearly describing' the present invention.

It is the object of this invention to produce a pilot iiame assembly ofanv improved construction that `permits of ready replacements andsubstitution of parts, in case the same becomes ingpetrative due to amechanical oi' electrical de'- More specically, it is the object of thislnvention to produce a pilot burner assembly and construction that canbe entirely removed from the main burner without affecting the operationof the main burner, so iar as the combustion of fuel is concerned, andin which the thermall couple or other heat responsive element forms apart of the pilot burner assembly, in such a way that it can be quicklyand easily removed and replaced, in case necessity should arise, withoutin the least interfering with the opera. tion of the main burner.

A further object of the invention is to provide a burner havingassociated therewith a tubular member which forms an integral part ofthe burner structure and into which the pilot burner assembly can beinserted.

A still further object is to produce a pilot burner assembly of a verysimple construction, in which the pilot llame entirely surrounds thethermal couple so as to always assure the transfer oi heat thereto.

Where a thermo-responsive device, such as a thermal couple or bimetallicswitch element is positioned adjacent to, but to one side oi', the pilotname, the latter may be diverted by air or gas currents in such a way asto prevent it from transmitting the necessary amount of heat to thethermo-responsive device. By positioning the thermo-responsive elementwithin a hollow tlame, it is obvious that it will always receive heatfrom the flame, regardless of the presenceor absence of gas currents.

Having thus set out some of the objects oi this invention, the inventionitself will now be described in detail and for this purpose referencewill be had to the accompanying drawing in which the invention has beenillustrated in its preferred form and in which:

Figure l is a top plan view of a typical gas burner of the type employedin heating installations;

Figure 2 is a section taken on line 2 2, Figure l, and shows theposition or the pilot burner assembly with relation to the burners andthe burner body;

Figure 3 is a fragmentary section to an enlarged scale, showing one formof pilot burner construction;

Figure 4 is a section taken on line I-l, Figure 3;

Figure 5 is a fragmentary section similar to that shown in Figure 3 andshows another form l or pilot burner construction;

Figure 6 is a section taken on line 6 6, Figure Figure 7 is afragmentary section similar to Figures 3 and 5 and shows anotherspecically different form of pilot burner construction and assembly; and

Figure 8 is a section taken on line 8-8 Figure 7.

In Figure 1 reference numeral III designates the hollow body of theburner and reference numeral Il designates the burner head sockets inwhich the burner heads or nozzle elements are positioned.

In the present drawing four burner head sockets have been shown, each ofwhich is circular and provided with a shoulder I2 on which a burner heador nozzle element rests. The burner body is hollow and the chambertherein has been designated by reference numeral I3. A threaded nippleI4 is provided at the central portion of the bottom wall I5 and this isconnected to the upper end of a throat mixer I6 which may be either anatmospheric mixer or an air pressuremixer. Since both of these types ofmixers are old and well known, they have not been illustrated in thedrawing.

A nozzle I1 of each multiple flame burner is provided with a centralcircular opening which has been designated by reference numeral I8 inFigures 3, 5 and 7. A tube I9 is positioned in coaxial relation with oneof the burner head y sockets and has its. lower end connected with thebottom wall I'5 of the burner body. Wall I5 is provided with an openingthat communicates withI the interior of tube I9. Although the interiorof tube I9 communicates with the atmosphere below the burner body, nogas can escape downwardly as the tube has an airtight seal with wall I5.The pilot burner assembly to which this invention relates, is positionedwithin tube I9 and will now bedescribed in detail.

In Figure 3 the pilot burner assembly has been `shown as consisting of atube that has an external diameter slightly less than the insidediameter of tube I9 and which can be inserted into tube I9 from thebottom. Tube 20 is held in position by means of a set screw 2l or othermechanical equivalent means. The lower end of tub 20 has an internalthread 22. Positioned within tube 20 and spaced from the inner wallthereof. is the tubular body 23 of the thermo-responsive element whichis provided at its upper end with a thermal couple hot junction 24. Athroat mixer tube 25 is communicated with an opening in the wall of tube20. Gas is directed into this throat mixer by means of a jet 26. The gasfrom the jet 26 mixes with air in the throat tube 25 and the mixtureflows out between the tubular member 23 and the inner surface of tube 20emerging in an annular stream which, when ignited forms a hollow flame21 that surrounds the thermal couple junction 24. The two wires thathave been designated by reference numeral 28 are the terminals of thethermal couple and extend to a valve control mechanism that has not beenshown.

As long as the gas is ignited, forming the hollow name 21, the thermalcouple generates the current necessary to retain the control valve inopen position, but if this flame is extinguished, this valve, which hasnot been shown, will close, thus assuring that no dangerous admission ofunburned fuel will be delivered to the furnace when the pilot name isnot burning.

In Figure 5 a slightly modiiied form of pilot burner assembly has beenshown. This view has been drawn to a somewhat larger scale and shows aconstruction in which tube 20 has been replaced by an upwardly extendingtubular por- 5 tion 20a of a ttlng resembling a T. The lateral chamber29 forms a mixing throat into which gas is introduced by means of a jet26. 'I'he thermal couple comprising parts 23 and 24 is introducedthrough a threaded opening 3| in the bottom of the T as shown in thedrawing. The gas iiows out between the inner surface of tube I9 and theouter surface of member 23 and forms a hollow ame entirely enclosing thethermal couple. A gas diffuser 32 may be positioned in the annularopening at the discharge end of tube I9. This may be formed from acorrugated metal strip like those designated by reference numerals 32 inFigures 2, 3 and 5.

In Figure 7 another modification has been shown. In this constructiontube 20, in Figure 3, has been replaced by a double tube, the outer onebeing designated by reference numeral 20h. A smaller tube 33 ispositioned within tube 20h and spaced therefrom forming an annularpassage 34. The two tubes are interconnected at their lower ends and theinterior of tube 33 terminates in a threaded opening 35 in which thethermal couple, comprising members 23 and 24, is threadedly connected.

Tube 2Gb is threadedly connected with the lower end of tube I9 and withthe burner wall I5 at 36. It will be seen that the thermal couple can bedisconnected from the tube for repair or replacement. Gas is introducedthrough the mixing throat 29 and emerges in an annular stream formingflameA 21, as shown in the drawing.

It will be seen from the above description that the pilot flame assemblycan be removed and replaced without interfering with the operation ofthe burner because tube I9 is part of the burner structure and preventsescape of gas downwardly. It is therefore possible to replace thethermal couple, in case this should become defective, withoutinterfering with the operation of the main or pilot burner.

The whole pilot burner assembly is constructed so as to be assembled asa unit and so that it may be introduced into tube I9 or separatedtherefrom in assembled form.

The construction shown in Figure 5 is the simplest, but all of them havethe common characteristic ofremovability and the production of anannular name'.

Although the pilot has been shown as associated with one burner of amulti-flame burner, it is evident that it can be used with a single ameburner or with any number of burners. The ame from the pilot controlledburner is transmitted to the others through the line burners 31 in whichare positioned corrugated metal strips 38, the corrugations preferablyextending diagonally as shown in the drawing.

The gas to the main burner can be supplied by means of an atmosphericmixing chamber or the gas and air can be introduced under pressure andmixed in the desired proportions in ways now quite common.

In the drawing' and in the description, the mixing throats have beenshown and described as extending laterally at an angle of substantiallyninety degrees. It is to be understood, however, 4that 'the angularrelation between the mixing throat andthe tube is optional and that itcan be inclined at any suitable angle. Where the character T isemployed, it is not to be understood in a limiting sense, but broadlyenough to include a. "Y fitting or any equivalent.

Having described the invention what is claimed as new is:

1.'A gas burner, comprising, a hollow body having a top wall and abottom wall, provided with axially aligned openings, the opening in thetop Wall being the larger, a tube having its lower end positioned in theopening in the bottom wall and its upper end in the opening in the topwall, an annular gas distributing nozzle surrounding the upper end ofthe tube, a'tubular member forming part of a thermo-responsive device,positioned in the tube a seal between the lower end of the tube and saidtubular member, the outside diameter of the tubular member being lessthan the inside diameter of the tube whereby an annular passageway forcombustible -fuel is formed, means for introducing a combustible gaseousmixture into the annular space which, when ignited, forms a tubularflame, and a thermal device at the upper end of the tubular member.

2. A gas burner comprising, a hollow body having a top wall and a bottomwall provided with aligned openings, the opening in the top wall beingthe larger, a tube secured at its lower end in the opening in the bottomwall, an annular gas distributing nozzle in the opening in the top wall,the upper end of the tube terminating in the opening in the nozzle, abranched fitting connected with the lower end of the tube, the lateralportion forming a mixing throat, a tubular member forming part of athermo-responsivedevice threadedly connected with the lower end of theiitting and extending upwardly to a point beyond the upper end of thefirst tube, a thermal element at the upper end of the tubular member,vand mean for introducing a combustible gaseous mixture through themixing throat into the space between the tube and the tubular memberwhich, when ignited, forms a tubular pilot flame that encloses thethermal element. I

3. A gas burner, comprising a hollow body tioned tube, inserted into thelatter'from below and removably associated therewith, a throat mixerextending laterally from and in communication with the interior of saidsecond tube, a tubular member forming part of a thermo-responsive deviceinserted into said second tube from below and removably connected withthe lower end thereof, the tubular memberhaving a diameter less than theinterior diameter of the second tube forming with the latter an annularcylindrical chamber, a thermal element at the upper end of the tubularmember, and means comprising said throat mixer for introducing acombustible gaseous mixture into said annular chamber which, whenignited, forms a tubular flame enclosing the thermal element.

4. A gas burner, comprising, a hollow body.

having a top wall and a bottom wall provided with aligned openings, theopening in the vtop wall being the larger, a tube secured at its lowerend in the opening in the bottom wall, the upper end of the tubeterminating in the opening in the top wall, an annular gas distributingnozzle in the opening in the top wall, and a pilot burner assemblyinsertable into the tube from below. said assembly comprising twoconcentric tubes. one positioned within the other, the two tubes beingconnected at the bottom, the outside diameter of the inner tube beingless thanl the inside diameter of the outer tube forming an annularcylindrical chamber, means for introducing a combustible gaseous mixtureinto the cylindrical chamber, a tubular member, forming part of a heatresponsive device, positioned in the inner tube and removably connectedwith the lower end thereof, and a thermal element at the having a topwall and a bottom wall provided with axially aligned openings, theopening in the top wall being the larger, a tube having its lower endsecured in the opening in the bottom wall, the upper end terminating inthe opening in the top wall, an annular gas distributing nozzle in theopening in the top wall, surrounding the upper end of the tube. a pilotburner assembly positioned in the tuba-said assembly coma tube of anoutside diameter slightly less than the inside diameter o! the firstmenupper end of the tubular member above the nozzle. whereby when thegas from the annular cylindrical chamber is ignited it will form ahollow flame surrounding the thermal element.

. PAUL J. PATCH.

REFERENCES CITED The following references are of record in the ile oi'this patent:

UNITED STATES PATENTS

